Pre-Installation Subfloor Requirements
All Subflooring must be:
- Structurally sound
- Clean: Thoroughly swept and free of all debris (If being glued down, subfloor must be free from wax, grease, paint, sealers, & old adhesives etc., which can be removed by sanding)
- Level: Flat to 3/16” per 10-foot radius
- Dry and will remain dry: Subfloor must remain dry year-round. Moisture content of wood sub floors must not exceed 11%, concrete must not exceed 3.5 as measured with a Tramex Commercial Concrete Moisture Meter.
Wood Sub floors:
- Must be flat to within 3/16” of a straight edge in a 10’ radius and without any abrupt height differences. “Hills” should be sanded down flat and valleys should be filled with a self-leveling cement compound developed for use with wood flooring such as Ardex K-15 Portland Leveling Compound or equal. Follow the manufacturer’s instructions for use.
- Must be structurally sound, with the recommended subfloor to be at least a 5/8” min. thick plywood installed onto joists, which are 16” on center and adequately sized for the length of the span. Prior to installing the wood floor, check to make sure the subfloor is well nailed to the joists. Re-nail any loose areas or sections with squeaks. Also check any areas where there is excessive up and down movement of the subfloor and joists and shore them up from below by adding blocking and/or additional support.
- The wood subfloor must be 10% M.C. or below. Take several moisture meter readings from different areas of the subfloor and save them as part of the permanent job record. Make sure, prior to installation of the wood flooring, that the space below the subfloor is not excessively damp as moisture from this area may later “wick” through the subfloor into the wood floor itself.